Holder for electron microscopy grids



Nov. 21, 1967 5. BROWN 3,353,656

HOLDER FOR ELECTRON MICROSCOPY GRIDS Filed March 12, 1965 2 Sheets-Sheet l INVENTOR SfqnLey B rown ATTORNEY NOV. 21, 1967 5, BROWN HOLDER FOR ELECTRON MICROSCOPY GRIDS 2 Sheets-Sheet 2 Filed March 12, 1965 IINVENTOR StgpLey Brown ATTORNEY v United States Patent 3,353,656 HOLDER FOR ELECTRON MICROSCOPY GRIDS Stanley Brown, Bronx, N.Y., assignor to Better Equipment for Electron Microscopy Inc., Bronx, N.Y., a corporation of New York Filed Mar. 12, 1965, Ser. No. 439,208 6 Claims. (Cl. 206-1) ABSTRACT OF THE DISCLOSURE This invention concerns a novel container for small articles comprising in combination a base and a cover, said base being indented to provide a plurality of cruciform recesses, said cruciform recesses comprising mutually perpendicular slots with re-entrant angles thereof rounded off to form convex shoulders, the cover being pivotally mounted on the base and provided with an access opening capable of registering with no more than one of the recesses at any given time.

This invention relates to a holder and dispenser for small fiat articles. In particular, this invention relates to a storage container and dispenser for small disc-shaped wire grids of the type used for mounting samples for electron microscopy and micrography.

Many methods have been devised by workers in the field for storing and filing electron microscopy specimens mounted on such grids, but all of the systems so far proposed have been unsatisfactory in one or more of various respects. Some of such systems, and in fact a majority of them, require an inordinate amount of storage space compared to the miniscule dimensions of the specimens themselves. Others made no provision for application of identifying indicia to the storage container, and thus required the preparation and application to the container of stickon labels and the like. In a majority of cases, the systems heretofore proposed have made no provision for storing the specimens in a way that would make it easy to recover the grid-mounted specimen from the storage container using forceps or the like. Some have stored the grids flat against the container bottom, leading to a likelihood of damage in case the grid was inadvertently stored sampleside-down, or in case the container was inverted. Moreover, containers designed for storage and filing of a plurality of specimen grids are commonly of a construction that requires exposure of a number of specimens to the atmosphere in order to gain access to any one specimen. This results in danger of contamination from airborne debris and microorganisms, and to a possibility that, in case the container is accidentally upset or dropped, a number of specimens may be thrown out of the container and irrevocably shuffled, completely invalidating the work that led to their preparation.

Storage and dispensing containers for various other kinds of small articles, such as pills and the like, are well known to the art, but in general have not proven satisfactory for the storage of grid-mounted specimens for electron microscopy. Many of such dispensing containers suffer from one or more of the disadvantages already mentioned. Most of such dispensers fail to provide any way of differentiating among the various recesses, and hence of identifying the contents of any given recess, and none of them provide means for holding the contents of the individual recesses in a position such as to be easily grasped by forceps or the like.

An object of this invention, therefore is to provide an improved specimen storage container.

Another object is to provide a storage system characterized by unusual compactness as compared with storage and filing systems heretofore proposed.

Still another object is to provide a storage container capable of accommodating a plurality of specimens, and having provision for identifying indicia to distinguish the contained specimens from each other and from the contents of other, similar containers.

Another important object of the invention is to provide a storage container for small flat objects such as specimen grids for electron microscopy, having a plurality of recesses, each recess being shaped to hold such a grid or the like in position to be easily grasped by a pair of forceps or similar instrument.

Still another object is to provide a storage container as aforesaid, which holds the sample-bearing surface or surfaces of the grid out of contact with the walls and floor of the recess.

Another object still is to provide a container such that access to any specimen can be had without exposing any other specimen to the danger of atmospheric contamination or accidental escape from the container.

A feature of the invention is the use of a base structure having a plurality of recesses in combination with a m0v able cover plate having an access opening capable of reg istering with no more than one of said recesses at a time.

Another feature is the use of modified cruciform recesses to receive and hold a specimen grid or the like in vertical disposition, out of contact with the walls of the recess.

Other objects, features and advantages will become apparent from the following more complete description and claims, and from the accompanying drawings, in which parts appearing in more than one view have been given the same reference numeral throughout.

In one particularly desirable aspect, this invention contemplates a container for small articles comprising in combination a base and a cover, said base being indented to provide a plurality of cruciform recesses, said cover being pivotally mounted on said base and being provided with an access opening capable of registering with no more than one of said recesses at any given time.

Referring now to the figures:

FIGURE 1 is a perspective drawing on an enlarged scale of a container according to one embodiment of the invention.

FIGURE 2 is a fragmentary view of a portion of the base member of the embodiment of FIGURE 1, with the cover removed.

FIGURE 3 is a plan view of another embodiment of the invention.

FIGURE 4 is a plan view of another embodiment of the invention.

Referring now more particularly to FIGURE 3, it will be seen that the container comprises a base 10 provided with a number of cruciform recesses 11 arranged in a circular array. Pivotally mounted atop the base is a cover plate 12 pivotally mounted on the base at a point 13 corresponding to the center of the circular array of recesses. Cover plate 12 is provided with an access opening 14 spaced from point 13 by the same distance as are recesses 11, so that it may be brought into registry with any of the recesses by manually rotating cover plate 12 about point 13, but of a size such that it can register with no more than one of the recesses at a time.

Outside of the circular area covered by cover plate 12, the base is preferably extended to form a rectangular outline, and for other purposes, as will presently appear.

The portions of the rectangular base not covered by the cover plate are preferably roughened, as at 15, to take pencil indicia for identification of the contents of the container.

A hinged outer cover 16 is also preferably provided, for further protection against dust which may collect as shown in FIGURE 1, for easier storage and filing,

around the cover plate and to prevent smearing of the pencil indicia mentioned above.

Preferably, outer cover 16 is made of clear plastic or the like, so that the pencil indicia may be seen without opening the container.

As also illustrated in FIGURE 3, permanent indicia such as numbers or letters 17 are preferably provided in association with the various recesses to enable the contents of each recess to be identified.

For most economical use of space, it is preferred that these indicia be located under cover plate 12, which should in such case be made of clear plastic or other transparent material. Locating the indicia under the cover plate leaves the remainder of the rectangular base free for pencil notations or the like.

The preferred shape of the recess, above described as cruciform, is shown in FIGURE 2, and may be described as being formed of two mutually perpendicular slots 18, with the re-entrant angles rounded otf to form convex shoulders 19 in place of the sharp corners that would otherwise be present. The length of each slot is slightly greater than the diameter of the sample-mounting grid 20, and the width of each slot is slightly greater than the thickness of the grid, so that the grid is held vertically in the recess. Rounded shoulders 19 diverge away from the ends of the slots 18, so that the grid is held by its edges only, and is not permitted to come into contact with the walls of the recess except at its edges. The fact that two mutually perpendicular slots are provided introduces the additional advantage that when the ends of one slot 18 are occupied by a grid, the ends of the other slot 18 provide clearance for the introduction of the jaws of a pair of forceps or the like, thus facilitating insertion and retrieval of the grid.

Another, and preferred, embodiment of the invention is illustrated in FIGURE 4. In this embodiment, the base is provided with two concentric rows of recesses 11, both lying beneath the same cover plate. Cover plate 12 is provided with a second access opening 14 in addition to the access opening previously described.

Access opening 14 registers with the recesses in the outer circle, while access opening 14 is spaced closer to the pivot point and registers with the recesses of the inner circle.

In the preferred construction, the arrangement of the recesses and of the access openings is such that no more than one recess is in registry with either of the access openings at any given time. In the illustrated embodiment, thi is accomplished by locating the two access openings on a common diameter of the cover plate, and staggering the recesses in such a manner that no recess of the inner circle is on the same diameter as any recess of the outer circle. Other spatial arrangements could be used to similar effect, for example, by locating each inner recess on the same radius as an outer recess, and spacing the access openings angularly from each other by a small increment.

An optional feature which is advantageous in many cases is also illustrated in FIGURE 4, namely a pair of more or less bullet-shaped recesses 21 in the base, outside the area covered by cover plate.

In the preparation of some types of specimen, such as histolocal specimens and the like, for electron microscopy, it is a common technique to embed the specimen in a suitable matrix such as methyl methacrylate, an epoxy resin or the like. The matrix is then hardened, by polymerization of the matrix or other suitable technique. The embedding process is carried out in a mold, which may be half of a gelatin medicine capsule, or a special mold made for the purpose. If made in a gelatin capsule, the round end of the block of hardened matrix is trimmed to a pyramidal shape. If a special mold is used, this step is taken care of in the molding operation. In either case, the embedded sample is in the form of a cylindrical block of matrix with a pyramidal end. Slices are then taken off the apex of the pyramid with a microtome, and these are mounted on a grid for electron microscopic examination.

In the embodiment of the invention as illustrated in FIGURE 1 and FIGURE 4, bullet-shaped recesses 21 are sized and shaped to accommodate the block of embedded specimen material. Thus, recesses 21 provide a convenient way of storing the block together with the mounted specimens taken from it, which provides for great convenience and accuracy in filing and storing specimens.

While this invention has been described with reference to certain preferred embodiments and illustrated by way of certain drawings, these are illustrative only, as many alternatives and equivalents will readily occur to those skilled in the art, without departing from the spirit and scope of the invention. The invention is therefore not to be construed as limited, except as set forth in the appended claims.

I claim:

1. A container for small articles comprising in combination a base and a cover, said base being indented to provide a plurality of cruciform recesses, said cruciform recesses comprising mutually perpendicular slots with re-entrant angles thereof rounded off to form convex shoulders, said cover being pivotally mounted on said base and being provided with an access opening capable of registering with no more than one of said recesses at any given time.

2. A container for small articles according to claim 1 wherein said cover is transparent, said base being provided with identifying indicia associated with said recesses, said indicia being located in the space covered by said transparent cover.

3. A container for small articles according to claim 1 wherein said pivotally-mounted cover is an inner cover covering said recesses in said base and an outer cover is hinged to said base, said outer cover removably overlying said base and said pivotally-mounted cover.

4. A container for small articles according to claim 1 wherein said pivotally-mounted cover overlies a portion only of said base and the said recesses are in the area of the base covered by said cover, said base being provided with a roughened flat surface in the area not covered by said cover, said access opening in said cover being registrable selectively with said recesses.

5. A container according to claim 1 for electron microscopy samples, wherein the plurality of recesses in said base are for sample grids and said pivotally-mounted cover overlies said recesses and a portion only of saidbase, said base being provided with a recess for an embedded specimen block in the area not covered by said cover, said access opening in said cover being registrable selectively with said recesses.

6. A container for small articles according to claim 1 wherein the length of each of said slots is slightly greater than the diameter of a sample mounting grid to be contained therein, and the width of each of said slots is slightly greater than the thickness of. said grid, so that said grid i held substantially vertically in said recess.

References Cited UNITED STATES PATENTS 2,832,659 4/1958 Akers 20616 X 2,953,242 9/1960 Shaw 20642 2,965,219 12/1960 Rhodin 2061 3,085,679 4/1963 Burrell 20642 3,095,085 6/1963 Meiyer 20642 3,143,207 8/1964 Wagner 20642 THERON E. CONDON, Primary Examiner,

MARTHA L, RICE, Examiner. 

1. A CONTAINER FOR SMALL ARTICLES COMPRISING IN COMBINTION A BASE AND A COVER, SAID BASE BEING INDENTED TO PROVIDE A PLURALITY OF CRUCIFORM RECESSES, SAID CRUCIFORM RECESSES COMPRISING MUTUALLY PERPENDICULAR SLOTS WITH RE-ENTRANT ANGLES THEREOF ROUNDED OFF TO FORM CONVEX SHOULDERS, SAID COVER BEING PIVOTALLY MOUNTED ON SAID BASE AND BEING PROVIDED WITH AN ACCESS OPENING CAPABLE OF REGISTERING WITH NO MORE THAN ONE OF SAID RECESSES AT ANY GIVEN TIME. 